Various techniques of printing color images in the form of monochrome prints (e.g., black-and-white prints) have been proposed hitherto. Japanese unexamined patent application publication No. 09-090922 discloses an image processing device that extracts color attribute of characters, then generates new attribute data from the color attribute extracted, and finally adds the attribute data to image data, thereby printing the image.
In the image processing device disclosed in Japanese unexamined patent application publication No. HEI-09-090922, the color data about the characters (text characters) constituting a text is uniquely determined with respect to the attribute data. Therefore, if a document has many characters to be printed in red, those parts printed in red will be underlined. This inevitably renders the document hard to read.